[Clinical study of watershed infarct dementia]

This clinical study of watershed infarct was carried out in two hospitals for elderly patients. The purpose of this study was an investigation of the clinical specificity of this type of infarct as compared with other types of infarcts. The most important point was to determine which patients with this type of infarct usually become demented. The items of investigation were brain CT findings, measurements of the width of the ventricles and the extent of sylvian fissures from CT images, blood pressure, past history of hypertension, diabetes mellitus, alcohol use and smoking, blood analysis of total cholesterol, HDL-cholesterol, hematocrit, hemoglobin A1 and uric acid and the incidence of patients in whom dementia had improved from the previous state. From CT findings, we classified all patients with brain infarcts into 4 groups; 173 patients with central infarcts, 56 patients with watershed infarcts, 20 patients with subcortical lesions of the Binswanger type and 11 patients with occlusion of main brain arteries. Among all investigated patients, there were 56 non-demented and 162 demented (74.3%) patients. Among the patients with watershed infarcts, there were 10 non-demented and 45 (81.8%) demented patients. In the group of demented patients with watershed infarcts, females were four times as many as males. Demented patients with watershed infarcts in the right hemisphere were twice as frequent as those with infarcts in the left hemisphere, while the number of non-demented patients with this type of infarct in right hemisphere was the same as that in the left hemisphere.(ABSTRACT TRUNCATED AT 250 WORDS)